FIELD OF THE INVENTION
[0001] Aspects of this invention relate generally to a method of manufacturing a sole assembly,
and, in particular, to a method of manufacturing a sole assembly formed of multiple
preforms having different colors.
BACKGROUND OF THE INVENTION
[0002] Conventional articles of athletic footwear include two primary elements, an upper
and a sole assembly. The upper provides a covering for the foot that comfortably receives
and securely positions the foot with respect to the sole assembly. In addition, the
upper may have a configuration that protects the foot and provides ventilation, thereby
cooling the foot and removing perspiration. The sole assembly is secured to a lower
portion of the upper and is generally positioned between the foot and the ground.
In addition to attenuating ground reaction forces, the sole assembly may provide traction,
control foot motions (e.g., by resisting over pronation), and impart stability, for
example. Accordingly, the upper and the sole assembly operate cooperatively to provide
a comfortable structure that is suited for a wide variety of activities, such as walking
and running. An insole may be located within the upper and adjacent to a plantar (i.e.,
lower) surface of the foot to enhance footwear comfort, and is typically a thin, compressible
member.
[0003] The sole assembly may incorporate multiple layers. Some footwear include only a midsole,
while others may also include an outsole secured to a bottom surface of the midsole.
The midsole, which is conventionally secured to the upper along the length of the
upper, is primarily responsible for attenuating ground reaction forces. The midsole
may also form the ground-contacting element of footwear. In such embodiments, the
midsole may include texturing, such as projections and recesses or grooves, in order
to improve traction. The outsole, when present, forms the ground-contacting element
and may be fashioned from a durable, wear-resistant material.
[0004] The midsole may be primarily formed from a resilient, polymer foam material, such
as ethylvinylacetate (EVA), that extends throughout the length of the footwear. The
properties of the polymer foam material in the midsole are primarily dependent upon
factors that include the dimensional configuration of the midsole and the specific
characteristics of the material selected for the polymer foam, including the density
of the polymer foam material. By varying these factors throughout the midsole, the
relative stiffness and degree of ground reaction force attenuation may be altered
to meet the specific demands of the activity for which the footwear is intended to
be used. In addition to polymer foam materials, conventional midsoles may include,
for example, one or more fluid-filled bladders and moderators.
[0005] The sole assembly may be formed of multiple portions, with some or all of the portions
having different colors. When EVA is formed in a mold assembly the color lines between
the different colored portions may bleed, decreasing the aesthetic appeal of the footwear.
[0006] WO 2013/023135 discloses a method of manufacturing a midsole that includes placing first and second
preforms into a midsole recess of a mold, with first and second portions of the mold
defining a first overflow chamber connected to the first recess; closing the mold
by positioning the first and second portions in contact with one another, and then
heating the mold for a predetermined period of time at a predetermined temperature
such that the first and second preforms melt and bond together to form a midsole.
[0007] US5725823A discloses a method of making a shoe sole having co-molded anti-skid insert. Raw unvulcanized
rubber sheet material for the insert, and raw unvulcanized rubber sheet material for
the main portion of the sole are placed in a mold and heated to fuse them together,
to vulcanize the rubber, and to produce an anti-skid pattern on the insert. The material
of the insert is preferably substantially the same as that of the main portion of
the sole, except for its color.
[0008] It would be desirable to provide a method of manufacturing a sole assembly for an
article of footwear that reduces or overcomes some or all of the difficulties inherent
in prior known processes. Particular objects and advantages will be apparent to those
skilled in the art, that is, those who are knowledgeable or experienced in this field
of technology, in view of the following disclosure and detailed description of certain
embodiments.
SUMMARY
[0009] The above objectives are achieved by a method of forming a sole assembly as defined
in the appended claims.
[0010] Features and advantages of manufacturing sole assemblies for footwear as disclosed
here will be further understood from the following detailed disclosure of certain
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIG. 1 is an elevation view of an article of footwear including an upper and a sole
assembly.
FIG. 2 is a plan view of a bottom of the sole assembly of FIG. 1.
FIG. 3 is a perspective view in exploded form of the sole assembly of FIG. 1.
FIG. 4 is a perspective view of a first mold assembly used to form a core portion
of the sole assembly of FIG. 3.
FIG. 5 is a perspective view of a second mold assembly used to form inserts and a
perimeter portion of the sole assembly of FIG. 3.
FIG. 6 is a section view of the bottom plate, sidewall plate, and core plate of the
mold assembly of FIG. 5 seen in a closed position and abutting relationship.
FIG. 7 is a section view of the bottom plate, sidewall plate, core plate, and top
plate of the mold assembly of FIG. 5 seen in a closed position and abutting relationship.
FIG. 8 is an elevation view of a third mold assembly having a top plate and a bottom
plate, shown in exploded form with a preform prior to its positioning in the bottom
plate.
FIG. 9 is an elevation view of the third mold assembly of FIG. 8, shown with the preform
in a recess in the bottom plate.
FIG. 10 is an elevation view of the third mold assembly of FIG. 8, shown in a closed
condition.
[0012] The figures referred to above are not drawn necessarily to scale, should be understood
to provide a representation of particular embodiments, and are merely conceptual in
nature and illustrative of the principles involved. Some features of the mold assemblies
used to manufacture a sole assembly have been enlarged or distorted relative to others
to facilitate explanation and understanding. The same reference numbers are used in
the drawings for similar or identical components and features shown in various alternative
embodiments. Mold assemblies for a sole assembly and methods of manufacture for such
a sole assembly as disclosed herein would have configurations and components determined,
in part, by the intended application and environment in which they are used.
DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS
[0013] An article of footwear 10 is depicted in FIG. 1 as including an upper 12 and a sole
assembly 14. For purposes of reference in the following description, footwear 10 may
be divided into three general regions: a forefoot region 16, a midfoot region 18,
and a heel region 20. Regions 16-20 are not intended to demarcate precise areas of
footwear 10. Rather, regions 16-20 are intended to represent general areas of footwear
10 that provide a frame of reference during the following discussion. Although regions
16-20 apply generally to footwear 10, references to regions 16-20 also may apply specifically
to upper 12, sole assembly 14, or individual components within either upper 12 or
sole assembly 14.
[0014] Upper 12 defines a void or chamber for receiving a foot. For purposes of reference,
upper 12 includes a lateral side 22, an opposite medial side 24, and a vamp or instep
area 26. Lateral side 22 is positioned to extend along a lateral side of the foot
(i.e., the outside) and generally passes through each of regions 16-20. Similarly,
medial side 24 is positioned to extend along an opposite medial side of the foot (i.e.,
the inside) and generally passes through each of regions 16-20. Upper 12 may also
include a closure mechanism, such as lace 28. Upper 12 also includes an ankle opening
30 that provides the foot with access to the void within upper 12.
[0015] Upper 12 may also include an insole (or sockliner, not shown), which is generally
a thin, compressible member located within the void for receiving the foot and proximate
to a lower surface of the foot. Typically, the insole, which is configured to enhance
footwear comfort, may be formed of foam, and optionally a foam component covered by
a moisture wicking fabric or textile material. Further, the insole or sockliner may
be glued or otherwise attached to the other components of footwear 10, although it
need not be attached, if desired.
[0016] Sole assembly 14 may be directly secured to upper 12 with an adhesive, for example.
Suitable adhesives are well known in the art and need not be discussed in greater
detail here. Sole assembly 14 may be secured to upper 12 with any other suitable fastening
means, and such other suitable means of sole assembly 14 to upper 12 will become readily
apparent to those skilled in the art, given the benefit of this disclosure.
[0017] It is to be appreciated that in certain embodiments, sole assembly 14 may serve as
a midsole, with an outsole (not shown) being secured to the bottom surface of the
midsole. In other embodiments, as illustrated here, the bottom surface of sole assembly
14 serves as the ground-engaging portion (or other contact surface-engaging portion)
of footwear 10.
[0018] Sole assembly 14 is responsible for attenuating ground (or other contact surface)
reaction forces to lessen stresses upon the foot and leg, and absorb energy. Sole
assembly 14 may also beneficially utilize such ground reaction forces for more efficient
toe-off, and control potentially harmful foot motions, such as over pronation. Sole
assembly 14 also forms a ground-engaging portion (or other contact surface-engaging
portion) of sole assembly 10. As noted above, in certain embodiments there is a separate
outsole member attached to the bottom surface of a midsole of sole assembly 14, while
in other embodiments there is no separate outsole member of the sole assembly. The
bottom surface of sole assembly 14 may include texturing to improve traction.
[0019] Sole assembly 14 is formed of a plurality of components having different colors.
The method used to form the sole assembly from a plurality of preforms having different
colors reduces the bleeding between the different colored portions, thereby enhancing
the aesthetics of sole assembly 14. The plurality of components may also have, in
addition to different colors, different physical properties or performance characteristics.
For example, the hardness of the various components may be different. It is to be
appreciated that any of the known physical properties or performance characteristics
for sole assemblies can be different for the different components of sole assembly
14, thereby altering the support, cushioning, load carrying capability, wear characteristics,
and tread life of sole assembly 14, for example. Other suitable physical properties
or performance characteristics will become readily apparent to those skilled in the
art, given the benefit of this disclosure.
[0020] As seen in the embodiment illustrated in FIG. 2, sole assembly 14 includes a first
core portion 32, one or more inserts 34, and a perimeter portion 36. Core portion
32 is formed of a first color, inserts 34 are formed of a second color, and perimeter
portion 36 is formed of a third color. While three colors are used in this embodiment,
it is to be appreciated that any number of different colors may be used for the various
components of sole assembly 14 in accordance with the method of manufacture described
below.
[0021] In certain embodiments, core portion 32, inserts 34, and perimeter portion 36 may
be formed of injection phylon (Ethylene Vinyl Acetate or "EVA"). The EVA may have
a Vinyl Acetate (VA) level between approximately 9% and approximately 40%. Suitable
EVA resins include Elvax®, provided by DuPont, and Engage, provided by the Dow Chemical
Company, for example. In certain embodiments, the EVA may be formed of a combination
of high melt index and low melt index material. For example, the EVA may have a melt
index between approximately 1 and approximately 50.
[0022] The EVA may also include various components including a blowing agent. The blowing
agent may have a percent weight between approximately 10% and approximately 20%. Suitable
blowing agents include azodicarboamide, for example. In certain embodiments, a peroxide-based
curing agent, such as dicumyl peroxide may be used. The amount of curing agent may
be between approximately 0.6% and approximately 1.5%. The EVA may also include homogenizing
agents, process aids, and waxes. For example, a mixture of light aliphatic hydrocarbons
such as Struktol® 60NS may be included. The EVA may also include other constituents
such as a release agent (e.g., stearic acid), activators (e.g., zinc oxide), fillers
(e.g., magnesium carbonate), pigments, and clays.
[0023] As illustrated in FIG. 2, perimeter portion 36 may form an entire outer periphery
38 of sole assembly 14. In other embodiments, perimeter portion 36 may form just a
portion of outer periphery 38. As illustrated here, perimeter portion 36 may also
completely surround an outer periphery 40 of core portion 32. As illustrated here,
inserts 34 may be completely surrounded by and contained within core portion 32.
[0024] Preforms of the components of sole assembly 14 are seen in exploded form in FIG.
3. As seen here, core portion preform 32' includes ribs 42 that extend downwardly
from its lower surface 44, and define a plurality of interior recesses 46. Each insert
preform 34' is configured to be seated or received in one of interior recesses 46.
Ribs 42 also define a shoulder 48 extending about at least a portion of core portion
preform 32'.
[0025] An aperture 50 extending through perimeter portion preform 36' defines an interior
lip 52 that is seated on shoulder 48 of core portion preform 32'. As seen in FIG.
2, in the finished product of sole assembly 14, the surface of aperture 50 abuts the
exterior perimeter of ribs 42.
[0026] As seen here in FIG. 3, surface irregularities 53 may be formed in the lower surfaces
of core portion preform 32', insert preforms 34', and perimeter portion preform 36'.
Surface irregularities 53 may take any desired form. In the illustrated embodiment,
surface irregularities 53 include a plurality of grooves 55 and lugs or projections
57, which form a grid of hexagonal projections 57 with corresponding grooves 55 surrounding
the projections, as seen more clearly in sole assembly 14 in FIG. 2. Surface irregularities
53 may serve aesthetic as well as performance purposes.
[0027] A method of forming sole assembly 14 that reduces bleeding between the colors of
core portion preform 32', insert preforms 34', and perimeter portion preform 36' will
now be described. As seen in FIG. 4, a first preform mold assembly 54, which is used
to form core portion preform 32', includes an upper plate 56 and a lower plate 58.
Upper plate 56 and lower plate 58 may be rotatably secured to one another with a hinge
60. A projection 61 extending downwardly from upper plate 56 and a lower recess 62
formed in lower plate 58 cooperate to define a core recess 63. As seen here, first
preform mold assembly 54 includes two core recesses 63 in order to simultaneously
form core portion preforms 32' for both left and right sole assemblies.
[0028] Recesses 64 formed in the bottom of core recess 63 serve to form ribs 42 when core
portion preform 32' is formed in first preform mold assembly 54. Recesses 64 may include
surface irregularities 66, which serve to form the mating surface irregularities 53
in the lower surface of ribs 42, as described above in conjunction with FIG. 2.
[0029] Core portion preform 32' is formed in core recess 63 of first preform mold assembly
54 in known fashion, with heated EVA being inserted into core recess 63. The resultant
EVA core portion preform 32' is later combined with insert preforms 34' and perimeter
preform 36' to form sole assembly 14, as described in greater detail below.
[0030] A second preform mold assembly 68, seen in FIG. 5, is used to form insert preforms
34' and perimeter portion preform 36'. Second preform mold assembly 68 includes a
bottom plate 70, a top plate 72, a core plate 73 positioned below top plate 72, and
a sidewall plate 74 positioned between bottom plate 70 and core plate 73. The plates
of second preform mold assembly 68 are connected by way of a hinge 76. A projection
78 extending downwardly from core plate 73, an aperture 80 extending through sidewall
plate 74, and a recess 82 formed in the top surface of bottom plate 70 cooperate to
define first, or insert, recesses 84 and a second, or perimeter, recess 86, seen in
FIGS. 6 and 7. As seen here, second preform mold assembly 68 includes two sets of
insert recesses 84 and two perimeter recesses 63 in order to simultaneously form of
insert preforms 34' and perimeter portion preforms 36' for both left and right sole
assemblies.
[0031] Surface irregularities 88 formed in the bottom surface of recess 82 serve to form
the mating surface irregularities 53 in the lower surface of inserts 34 and perimeter
portion 36, as described above with respect to core portion 32 and in conjunction
with FIG. 2.
[0032] A perimeter portion preform 36' with insert preforms 34' seated therein and formed
in second preform mold assembly 68 is shown here for illustrative purposes in the
right recess 82 of bottom plate 70. It is to be appreciated that any number of insert
preforms 34' may be formed in second preform mold assembly 68. In the illustrated
embodiment, there are three insert preforms 34' used to form sole assembly 14. It
is to be appreciated that a single insert preform 34', or any number of insert preforms
34', may be used to form sole assembly 14.
[0033] As seen in FIG 6, sidewall plate 74 and core plate 73 are pivoted downwardly into
a closed position onto bottom plate 70. The heated EVA for forming perimeter portion
preform 36' is then injected through a first gate 90 formed in core plate 73, as illustrated
with arrow A. The EVA for perimeter portion preform 36' is thus positioned within
perimeter recess 63.
[0034] After heated EVA is injected into perimeter recess 63, top plate 72 is then pivoted
down into a closed position on core plate 73. Heated EVA for forming insert portions
34' is then injected through a second gate 92 formed in top plate 72 and core plate
73 into insert recesses 84. Thus, the configuration of the second preform mold assembly
68 allows for the simultaneous formation of two different colors of the injected EVA
material to form both insert preforms 34' and perimeter portion preform 36'.
[0035] All of the preforms, that is, core portion preform 32', insert preforms 34', and
perimeter portion preform 36', each having a different color, are then preassembled
into a single sole assembly preform 94. As illustrated in FIGS. 8-10, this unitary
sole assembly preform 94, formed of all three colored materials is then placed in
a single step into a recess 96 formed in a heated bottom plate 98 of a third mold
assembly 100, as depicted by arrow C. Once sole assembly preform 94 is seated in recess
96, a top plate 102 of third mold assembly 100 is positioned on bottom plate 98 so
as to close third mold assembly 100. Sole assembly preform 94 is then subjected to
heat within third mold assembly 100 for a predetermined time period so that core portion
preform 32', insert preforms 34', and perimeter portion preform 36' bond to one another,
thereby forming sole assembly 14.
[0036] In certain embodiments, third mold assembly 100 is maintained at a temperature between
approximately 170°C and 180°C for approximately 10 minutes. The specific temperature
and time period used to form sole assembly 14 in third mold assembly 100 can be varied,
in known fashion, depending on the particular EVA used.
[0037] In known fashion, after sole assembly 14 is removed from third mold assembly 100,
sole assembly 14 will expand. Sole assembly 14 then goes through typical stabilization
steps, including cooling and trimming, as necessary.
[0038] By inserting the entire unitary preform 94 into recess 96 at one time, bleeding between
the different colors of the portions of preform 94 as sole assembly 14 is formed is
reduced, since all of the materials start melting at the same time upon insertion
into third mold assembly 100.
[0039] In certain embodiments, as seen in FIG. 2 and noted above, the surface irregularities
53 may form a defined pattern. As seen in the embodiment illustrated here, surface
irregularities 53 form a grid of hexagonal projections 57 with corresponding grooves
55 formed about projections 57. In such an embodiment, it may be desirable to have
the boundaries between the different colors, that is, the color lines between core
portion 32, inserts 34, and perimeter portion 36 not match or follow exactly along
the edges of projections 57 or grooves 55. Any bleeding between the different colors
will be more observable if the color lines are attempted to line up with the edges
of projections 57 and grooves 55. The user's eye will be less likely drawn to the
bleeding if the color lines move across projections 57, rather than exclusively along
the perimeters of projections 57.
[0040] Thus, while there have been shown, described, and pointed out fundamental novel features
of various embodiments, it will be understood that various omissions, substitutions,
and changes in the form and details of the devices illustrated, and in their operation,
may be made by those skilled in the art within the scope of the appended claims. Substitutions
of elements from one described embodiment to another are also fully intended and contemplated.
It is the intention, therefore, to be limited only as indicated by the scope of the
claims appended hereto.
1. A method of forming a sole assembly (14), comprising the steps of:
positioning a plurality of preforms (32', 34', 36') having different colors together
to form a sole assembly preform (94), wherein the plurality of preforms includes a
first preform (32') of a first color, a second preform (34') of a second color, and
a third preform (36'), wherein an outer periphery of the second preform (34') is completely
surrounded by the first preform (32'), and wherein an outer periphery of the first
preform (32') is completely surrounded by the third preform (36');
placing the sole assembly preform in a recess (96) in a first portion (98) of a heated
mold assembly (100);
closing the mold assembly such that a second portion (102) of the mold assembly is
above and in contact with the first portion;
subjecting the sole assembly preform to heat for a predetermined amount of time such
that the plurality of preforms bond to one another to form a sole assembly;
opening the mold assembly; and
removing the sole assembly from the mold assembly.
2. The method of claim 1, wherein a first preform (32') of the plurality of preforms
is formed in a first preform mold assembly (54).
3. The method of claim 2, wherein a bottom surface of a recess (64) of the first preform
mold assembly (54) includes at least one surface irregularity (66).
4. The method of claim 3, wherein at least one surface irregularity (66) comprises one
of a projection and a recess.
5. The method of claim 1, wherein the second preform (34') and the third preform (36')
of the plurality of preforms are formed in a second preform mold assembly (68).
6. The method of claim 5, wherein the second preform (34') and the third preform (36')
have different colors.
7. The method of claim 5, wherein bottom surfaces of each of a first recess (82) and
a second recess (82) of the second preform mold assembly (68) include at least one
surface irregularity (88).
8. The method of claim 7, wherein at least one surface irregularity (88) on the bottom
surface of each of the first recess and the second recess comprises one of a projection
and a recess.
9. The method of claim 1, wherein a plurality of second preforms (34') having the second
color are used to form the sole assembly preform (94).
10. The method of claim 1, wherein the plurality of preforms (32', 34', 36') have different
performance characteristics.
11. The method of claim 1, wherein the first preform (32') is formed in a first preform
mold assembly (54) and/or the second preform (34') and the third preform (36') are
formed in a second preform mold assembly (68).
12. The method of any one of claims 1 to 11, wherein there are boundaries between the
different colors of the adjacent preforms.
1. Verfahren zum Bilden einer Sohlenanordnung (14) mit den Schritten:
gemeinsames Anordnen einer Vielzahl von Vorformlingen (32', 34', 36') in unterschiedlichen
Farben, um einen Sohlenanordnungsvorformling (94) zu bilden, wobei die Vielzahl von
Vorformlingen einen ersten Vorformling (32') einer ersten Farbe, einen zweiten Vorformling
(34') einer zweiten Farbe und einen dritten Vorformling (36') aufweist, wobei ein
Außenumfang des zweiten Vorformlings (34') vollständig durch den ersten Vorformling
(32') umgeben ist und wobei ein Außenumfang des ersten Vorformlings (32') vollständig
durch den dritten Vorformling (36') umgeben ist;
Platzieren des Sohlenanordnungsvorformlings in einer Ausnehmung (96) in einem ersten
Abschnitt (98) einer erhitzten Gusswerkzeuganordnung (100);
Schließen der Gusswerkzeuganordnung, so dass ein zweiter Abschnitt (102) der Gusswerkzeuganordnung
über dem ersten Abschnitt und mit demselben in Kontakt ist;
Aussetzen des Sohlenanordnungsvorformlings gegenüber Wärme für eine vorbestimmte Zeitdauer,
so dass die Vielzahl von Vorformlingen aneinanderbinden, um eine Sohlenanordnung zu
bilden;
Öffnen der Gusswerkzeuganordnung und
Entnehmen der Sohlenanordnung aus der Gusswerkzeuganordnung.
2. Verfahren nach Anspruch 1, wobei ein erster Vorformling (32') aus der Vielzahl von
Vorformlingen in einer ersten Vorformling-Gusswerkzeuganordnung (54) gebildet ist.
3. Verfahren nach Anspruch 2, wobei eine Bodenoberfläche einer Ausnehmung (64) der ersten
Vorformling-Gusswerkzeuganordnung (54) mindestens eine Oberflächenunregelmäßigkeit
(66) aufweist.
4. Verfahren nach Anspruch 3, wobei mindestens eine Oberflächenunregelmäßigkeit (66)
eines von einem Vorsprung und einer Ausnehmung aufweist.
5. Verfahren nach Anspruch 1, wobei der zweite Vorformling (34') und der dritte Vorformling
(36') aus der Vielzahl von Vorformlingen in einer zweiten Vorformling-Gusswerkzeuganordnung
(68) gebildet sind.
6. Verfahren nach Anspruch 5, wobei der zweite Vorformling (34') und der dritte Vorformling
(36') unterschiedliche Farben haben.
7. Verfahren nach Anspruch 5, wobei Bodenoberflächen einer ersten Ausnehmung (82) und
einer zweiten Ausnehmung (82) der zweiten Vorformling-Gusswerkzeuganordnung (68) jeweils
mindestens eine Oberflächenunregelmäßigkeit (88) aufweisen.
8. Verfahren nach Anspruch 7, wobei mindestens eine Oberflächenunregelmäßigkeit (88)
auf der Bodenoberfläche der ersten Ausnehmung und der zweiten Ausnehmung jeweils eines
von einem Vorsprung und einer Ausnehmung aufweist.
9. Verfahren nach Anspruch 1, wobei eine Vielzahl von zweiten Vorformlingen (34') in
der zweiten Farbe zur Bildung des Sohlenanordnungsvorformlings (94) verwendet werden.
10. Verfahren nach Anspruch 1, wobei die Vielzahl von Vorformlingen (32', 34', 36') unterschiedliche
Leistungseigenschaften haben.
11. Verfahren nach Anspruch 1, wobei der erste Vorformling (32') in einer ersten Vorformling-Gusswerkzeuganordnung
(54) gebildet ist und/oder der zweite Vorformling (34') und der dritte Vorformling
(36') in einer zweiten Vorformling-Gusswerkzeuganordnung (68) gebildet sind.
12. Verfahren nach einem der Ansprüche 1 bis 11, wobei zwischen den unterschiedlichen
Farben der aneinander angrenzenden Vorformlinge Begrenzungen vorhanden sind.
1. Procédé de fabrication d'un ensemble de semelle (14) comprenant des étapes consistant
à :
positionner un ensemble de préformes (32', 34', 36') ayant différentes couleurs les
unes avec les autres pour former une préforme d'ensemble de semelle (94), les préformes
de l'ensemble de préformes comprenant une première préforme (32') ayant une première
couleur, une seconde préforme (34') ayant une seconde couleur et une troisième préforme
(36'), la périphérie externe de la seconde préforme (34') étant totalement entourée
par la première préforme (32') et la périphérie externe de la première préforme (32')
étant totalement entourée par la troisième préforme (36'),
mettre en place la préforme de l'ensemble de semelle dans une cavité (96) d'une première
partie (98) d'un ensemble de moule chauffé (100), fermer l'ensemble de moule de sorte
qu'une seconde partie (102) de celui-ci soit située au-dessus et en contact avec la
première partie,
soumettre l'ensemble de préforme de semelle à de la chaleur pendant une durée prédéfinie
de sorte que les préformes de l'ensemble de préformes se lient pour former l'ensemble
de semelle,
ouvrir l'ensemble de moule, et
enlever l'ensemble de semelle de l'ensemble de moule.
2. Procédé conforme à la revendication 1,
selon lequel une première préforme (32') de l'ensemble de préformes est formée dans
un premier ensemble de moule de préforme (54).
3. Procédé conforme à la revendication 2,
selon lequel la surface inférieure d'une cavité (64) du premier ensemble de moule
de préforme (54) a au moins une irrégularité de surface (66).
4. Procédé conforme à la revendication 3,
selon lequel l'irrégularité de surface (66) comporte une saillie et/ou un renfoncement.
5. Procédé conforme à la revendication 1,
selon lequel la seconde préforme (34') et la troisième préforme (36') de l'ensemble
de préformes sont formées dans un second ensemble de moule de préforme (68).
6. Procédé conforme à la revendication 5,
selon lequel la seconde préforme (34') et la troisième préforme (36') ont des couleurs
différentes.
7. Procédé conforme à la revendication 5,
selon lequel les surfaces inférieures d'une première cavité (82) et d'une seconde
cavité (82) du second ensemble de moule de préforme (68) ont au moins une irrégularité
de surface (88).
8. Procédé conforme à la revendication 7,
selon lequel au moins une irrégularité de surface (88) de la surface inférieure de
la première cavité et de la seconde cavité comporte une saillie ou un renfoncement.
9. Procédé conforme à la revendication 1,
selon lequel plusieurs secondes préformes (34') ayant la seconde couleur sont utilisées
pour former la préforme de l'ensemble de semelle (94).
10. Procédé conforme à la revendication 1,
selon lequel les préformes de l'ensemble de préforme (32', 34', 36') ont des caractéristiques
de performances différentes.
11. Procédé conforme à la revendication 1,
selon lequel la première préforme (32') est formée dans un premier ensemble de moule
de préforme (54) et/ou la seconde préforme (34') et la troisième préforme (36') sont
formées dans un second ensemble de moule de préforme (68).
12. Procédé conforme à l'une quelconque des revendications 1 à 11, selon lequel il y a
des délimitations entre les différentes couleurs des préformes adjacentes.